“The apps have been very critical in helping me achieve my goals,” he said.

Demargel used apps to monitor his weight, bike routes, even what he ate.

What many people may not know is that apps that ask for personal information often share it with third parties which puts user privacy at risk.

“I’ve made a choice that being that this was going to help me from a health perspective, that I would take the privacy risk,” Demargel said.

Officials said not everybody may be as comfortable with that concept as Demargel.

“I think that’s troubling. In the health and fitness context where consumers are used to thinking about sharing their information in the traditional provider context. I think they might be surprised about the collection of information that’s happening,” Federal Trade Commission spokesperson Cora Tung Han explained.

Information sharing is all about marketing, experts told CBS 2.

“If you have high-blood pressure and you are telling the app, ‘I have high blood pressure’, you should expect you’re going to get an advertisement for high blood pressure medicine,” Application Developer’s Alliance representative Jon Potter said.

The FTC has stepped in and wants app providers to let users know who is tracking them.

“We do look at whether or not apps are honoring what they say in their privacy policies and also whether or not they are living up to what they say to consumers in the app itself about what they’re doing with their information,” Tung Han said.

For personal protection the FTC suggests reading app privacy policies and only proving information that you are comfortable sharing.